1. Field of the Invention
The present invention relates to a process and apparatus for producing a winding for transformers. More particularly, the present invention relates to a process for producing a transformer winding from angularly profiled (rectangularly cross-sectioned) wires, wherein the profiled wires are brought together in a twist head and twisted to form a twisted conductor. The individual wires are brought together to form two adjacent groups of wires, each group including two flat sides. The individual wires positioned at the flat sides, i.e., the respective top and bottom conductors, of each of the adjacent groups extend obliquely in opposite directions so as to switch sides through an offset on the narrow sides of the cross section. Concurrently, the top conductor of group 1 extends over to group 2 to become the top conductor of group 2 (the previous top conductor of group 2 is now second from the top), and the bottom conductor of group 2 extends over to group 1 to become the bottom conductor of group 1 (the previous bottom conductor of group 1 is now second from the bottom). Thus, the top two (or bottom two) individual wires, which are disposed on top of each other (before twisting) in their cross section are disposed next to each other (after twisting), and are spaced from each other if necessary. The resulting twisted conductor is enclosed in insulation in at least sectionally.
2. Description of Background and Relevant Information
A device for producing twisted conductors is disclosed in EP-A 408,832. The production of a twisted conductor is also disclosed in principle.
In producing a winding for a transformer, conventionally, the twisted conductor has been produced at a first station and the winding for the transformer has been produced at another station. In performing such an operation, the twisted conductor is therefore wound on a transport drum while at the first station. In most cases, the transport drum has a considerably smaller diameter than the core diameter of the transformer winding. Accordingly, in taking the twisted wire from the transport drum and then producing the winding at another station, deformation of the twisted conductor is unnecessarily done twice.
A method for rolling a conductor is disclosed in U.S. Pat. No. 3,747,205. Such method of rolling up conductors is performed in connection with pancake coils which are wound on a core with a rectangular cross section. This structure is intended to prevent displacement or slipping of the insulation which occurs with rectangular cores.